# Smoking room ventilation - how many CFM?



## StogieNinja

Well, the wall is built, we're working on insulation, rocking, and taping. Next we'll paint, but before that we need to put in ventilation. One of the walls is an exterior wall, so I'm going with and exterior-mounted ventilation fan to minimize the noise from the fan. 

My question is, what CFM will be adequate for a 10"x12" room, with 10" ceilings? I want to be able to have 4-6 guys, maybe up to 8, be able to be smoking in there comfortably. 

Anyone have any recommendations for what minimum CFm I'll need, and/or a recommendation for a particular brand/type of fan? Is like Otto be adjustable for when there are only 1-2 guys and we want it a bit quieter. 

Thanks all!


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## kapathy

i use this in my smoking room 18X12.....
http://www.amazon.com/Vortex-VTX600...YTLG/ref=sr_1_1?ie=UTF8&qid=1325465817&sr=8-1

I also have my induct and output verticle so it draws straight from the room (no pipe in) and then discharges out. You could theoretically Y the induct line and have 2 places to draw from. I hooked mine up to a dimmer switch, its pretty quiet and does a decent job. I thought it would suck more air through it but really the cfm is how much air it pushes. But the main thing that is going to help is fresh air intake.... you need to create a draft between fresh air in and smoke out otherwise the fan is going to try to create a vaccuum which it never will in a room that size. Does your room have any windows? A small fan in the window bringing air in blowing towards the discharge would work well. although i think in your install a ceiling mount intake (or high wall) in addition to a ceiling fan with the rotation set to draw air up might work well. Although it also might create alot of air turbulance. I hope this makes sense to you, if not I'll try to explain more.


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## loulax07

do a search for CFM calc, i've used it before
you need to know the volume which you already know


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## StogieNinja

I was going to add a small fresh air intake at the bottom of the same exterior wall, to hopefully create a draft where the air is brought up and then out. Maybe with some kind of small heater in the intake to keep the room from freezing.


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## kapathy

rrreeeaaallllyyyyyy long pm sent


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## Just1ce

I run a slightly larger room with 2 inline fans very similar to that one. I have 2 fantechs that each are rated at 417 cfm. Any bends in the line will reduce performance slightly, but mine works perfectly on lower settings. I have a speed controller hooked up to each. 

I don't have a dedicated fresh air intake. My room is in the basement, and I do have intakes in the wall of the room, but it easily pulls in outside air from around the door jambs in the basement. It does make the basement a little cold, but that doesn't affect anyone else in the house as most of it is unfinished. This may not be ideal for everyone, but it works for me. I didn't want to spend tons of money on a fresh air exchanger that would keep up with 600-800 cfm exhaust fans. 

They key to making this work in my house was putting up 6mm plastic sheeting behind the drywall and on the ceiling. I also used duct tape to seal up all of the seems where the plastic meets for good measure. The plastic prevents any smoke/odor from escaping the room and the few gaps in the room allow fresh air to move in as the fans are working.

An exterior mounted fan is a good idea to prevent noise. Mine are a bit noisy as they are mounted in the ceiling of the room. I also do not have ducting with a smooth interior. I think that contributes to the noise level as the air makes noise as it passes across the interior ridges. It's noisy, but not overbearing. I can still listen to the TV and have a conversation with them on full, but I haven't yet really needed them on full. They have done the trick at less than 50% speed.


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## [email protected]

*Rooftop ventilation Fan?*

Hello fellow smokers,
I've read this older thread with interest and am planning to follow the guidance to get a "large cfm exhaust fan" but I'm having trouble finding one that meets my application. I've turned my whole living room/dining room into a pub room and plan to put in a ceiling fan to pull the air up into the vaulted ceiling then exhaust.
First: Has anyone heard of or used Purifan? It is a filtered ceiling fan that, although it doesn't look cool, might fulfill the filtration needs of a smoking room (often referenced in addition to ventilation).
Second: I don't have an attic over this room so plan to exhaust directly out the ceiling. Most fans that I've found are attic fans that work off of solar. Anyone know of another option?
Third: I did see a post referencing Fantech Votex in-duct fans as being very powerful, but I don't really have a duct that I can get to. Any ideas how to install this, perhaps out the side of the building (external wall)?

Looking forward to smoking all year round here in Michigan!


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## StogieNinja

Oh, this thread makes me sad. It's been almost six years and I still don't have a fan installed!!! Three babies in 16 months will do that do you...


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## MyFatherFan

StogieNinja said:


> Oh, this thread makes me sad. It's been almost six years and I still don't have a fan installed!!! Three babies in 16 months will do that do you...


I hear you on that one. Got another one on the way and wife took over the original smoking room for her nail and sewing room. I just got the OK to build myself an office downstairs so before the newborn gets here it is getting done.

Time to get back at it and get it done!
@[email protected] I would suggest starting a new thread instead of piggy backing of this old thread you came across. It will likely help you get more feedback on your question as well.

Welcome!


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## Matfam1

I’m a HVAC tech, I do a lot of ventilation engineering. Let me know the specs, and I can help you come up with a workable solution.


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## [email protected]

Thanx Matfam1,
My room is 16x35 with a peak ceiling. The problem that I see is that this was my living room that has a wide open wall into the entry way and the rest of the house. I have a laundry room at the end of that hall with a window I could open for makeup air. I'm mostly interested in a solution that can continuously "drain" that room of smoky air so it cannot infiltrate into the rest of the house. The alternative will be to wall in the entry way with glass block or French doors. I'm counting on the ceiling fan above the "smoking table" to draw the smoke up and away from the room. Then, of course, suck the raised smoky air out...

Thoughts?


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## Matfam1

[email protected] said:


> Thanx Matfam1,
> 
> My room is 16x35 with a peak ceiling. The problem that I see is that this was my living room that has a wide open wall into the entry way and the rest of the house. I have a laundry room at the end of that hall with a window I could open for makeup air. I'm mostly interested in a solution that can continuously "drain" that room of smoky air so it cannot infiltrate into the rest of the house. The alternative will be to wall in the entry way with glass block or French doors. I'm counting on the ceiling fan above the "smoking table" to draw the smoke up and away from the room. Then, of course, suck the raised smoky air out...
> 
> Thoughts?


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## Matfam1

With the wide open space, there are far to many variables for me to analyze and give you and exact plan. 

Here’s, what international mechanical code would require: 2352cfm. Thats almost 6 tons (72000 btuh @ 20F temp difference) of air flow. To keep smoke laden air from migrating to the rest of the house, this smoking area will need to be negative in relationship to the rest of the house and you will need to over come the other air movement influences in the room. There are a variety of factors at work including air movement and thermal differences between spaces. Down and dirty, I’m guessing that your desired effect could be achieved with someplace between 400 and 800 cfm. You would likely need and exhaust fan and a positive pressure make-up air fan (box fan in a window) to get what you want. This is just a guess, if you enclosed the room your odds go way up.


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## StogieNinja

Matfam1 said:


> I'm a HVAC tech, I do a lot of ventilation engineering. Let me know the specs, and I can help you come up with a workable solution.
> 
> Sent from my iPad using Tapatalk


 @Matfam1, my room is 10x12 with 10ft ceiling. I was thinking 400cfm and a makeup air fan


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## Matfam1

How many people do you expect to have smoking at a time?


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## Matfam1

Mechanical code for a smoking lounge calls for design occupancy of .07 people per sqft and 60 cfm per person. In your case it’s 8.4 people and 504 cfm. That’s a lot of airflow, also a lot of heating or cooling. 

400 cfm would certainly do the job for you. How do you plan to duct it?


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